This application is a national entry application of International Patent Application Serial No. PCT/NL00/00532, entitled xe2x80x9cMethod and Apparatus for Mounting or Dismounting a Semi-Automatic Twist-Lockxe2x80x9d to A. J. Klein Breterler, et al., having an international filing date of Jul. 26, 2000, and claiming priority to Netherlands Patent Application Serial No. 1012849, having a filing date of Aug. 18, 1999, and the specifications thereof are incorporated herein by reference.
(Not Applicable)
(Not Applicable)
1. Field of the Invention
The invention firstly relates to a method for mounting or dismounting a semi-automatic twistlock at a corner of a container, wherein the twistlock is mounted or dismounted on a quayside where a ship may be docked for loading or unloading.
The invention also relates to a loading or unloading terminal to be used with such a method.
2. Description of Related Art
A twistlock such as, for example, disclosed in the international patent application WO 96/15053 (PCT/SE 95/01337), serves to secure containers of the kind transported on sea-going ships against moving and going overboard. Since its introduction at the beginning of the seventies of the 20th century, different variants of the twistlock have been brought on the market. The original variants were operated completely manually, whereas nowadays the so-called semi-automatic type is used more and more.
A twistlock consists of a housing, an operating handle and two cones, which have to intermate with the containers, and which have to interlock the stacked containers. The two cones of the twistlocks are attached to an axis that is rotatable in the housing.
In the prior art a semi-automatic twistlock is mounted as follows: After a container has been placed under a quayside crane, the crane driver lifts the container by means of the crane and veers it to approximately 1.5 m above the ground in the vicinity of two persons who mount the twistlocks. Each of these persons walks with a twistlock in the hand to a corner of the container, inserts said twistlock into the respective recess and moves the operating handle such that the twistlock is locked into place. The same operation has to be carried out for the two remaining corners of the container. After this has been done, the crane driver transports the container to the ship. The semi-automatic embodiment of the twistlock ensures that the same interlocks automatically with the other container onto which the respective container is placed.
To release, each twistlock has to be unlocked manually on deck such as to release the lock with the container underneath. The twistlocks coupled to the top containers then have to be dismounted in the reverse order to that described above for mounting.
This known method of operation has the following drawbacks: There are many kinds of semi-automatic twistlocks in use which means that the quayside crew requires and continues to require a considerable amount of instruction and training. In addition, mounting and dismounting the twistlocks is heavy and unpleasant work. Each twistlock weighs approximately 7 to 8 kg and in order to mount it, it needs to be lifted from a bin standing on the ground and inserted at a height of approximately 1.5 m. Apart from the fact that this is heavy and unpleasant work which has to be carried out in all weathers, it is also dangerous because the work has to be done under the crane from which the container is suspended and on the traffic lanes intended for the vehicles transporting the containers to and from the loading site. A further serious drawback is that these operations prolong the crane cycle of the crane loading and unloading the ship, which has a negative effect on the crane""s performance, while also raising the moorage fee for the ships to be loaded and unloaded.
DE-A-43 17 996 discloses a method and an apparatus for mounting or dismounting a semi-automatic twistlock at a corner of a container, wherein the twistlock is mounted or dismounted in a loading or unloading terminal installed on the quayside where a ship may be moored that is to be loaded or unloaded, the container being placed by means of the quay crane on a trolley bearing the container. Said trolley used in DE-A-43 17 996 is provided with features for operating the twistlock. A quay crane places the containers to be handled on the trolley and after operating the twistlock, a straddle carrier is needed to move the respective container. The drawback of the method and apparatus known from DE-A-43 17 996 is that a separate loading or unloading terminal is needed for every quay crane, while its dimensions need to be adjusted to the dimensions of the containers. Another drawback is that the operation of the loading or unloading terminal influences the cycle of the quay crane which, among other things, is disadvantageous in the event of malfunction. A further disadvantage is that the prior art loading or unloading terminal has to be moved together with the quay crane and moreover, that as a consequence, the operating crew stays continuously in the danger zone.
It is the object of the invention to provide a method and apparatus wherein said drawbacks do not occur, or are at least greatly reduced. To this end the method according to the invention is characterized in that the container is lifted off the trolley, after which an implementation apparatus is activated for mounting or dismounting the twistlock, and in that subsequent to this operation having been carried out, the container is replaced on the trolley and the trolley leaves the loading or unloading terminal.
This method may be realized especially well in a loading or unloading terminal which is embodied as a portal under which the container carried by the trolley may be placed, which portal is provided with a lifting device for lifting the container off the trolley, and which has at least one implementation apparatus for mounting or dismounting a twistlock at a corner of the container, which implementation apparatus possesses a holder for the twistlock, which holder comprises a clamping member for a housing of the twistlock and a rotating member for rotating a cone of the twistlock, and which is characterized in that the carrier member is placed on a transport device guided along the container. The carrier member is preferably embodied with arms forming a parallelogram whose first ends are coupled with the transport device and whose second ends are coupled with the holder.
This has the advantage that on the one hand the implementation apparatus can be kept substantially outside the path followed by the container and on the other hand, that this equips the carrier member for positioning the holder under a corner of a container as well as above a supply tray, while the apparatus can be used for containers of diverse dimensions.
A further desirable embodiment of the loading and unloading apparatus according to the invention is characterized in that the holder is adjustable to a first position with the twistlock pointing upward, and a second position with the twistlock pointing downward. In this manner a simple movement suffices to change the position in which the twistlock is being mounted on or dismounted from the container, and the position in which the twistlock is taken to or from the supply tray.
In the terminal according to the invention it is possible to provide fully automated mounting and dismounting of semi-automatic twistlocks. The advantage that the invention affords in addition to the improvement regarding safety, is in particular the fact that the method and the apparatus may be employed outside the actual crane area, so that any hindrance to the crane cycle is avoided altogether. Alternatively, instead of operating the loading or unloading terminal fully automated, it is also possible to operate it such as to be semi-automated and, as the occation arises, to mount or dismount the twistlock manually. The full advantage resulting from an unhindered crane cycle is then retained, however, the gain in safety is at least partially forfeited.
Advantageously the loading or unloading terminal is equipped such that four implementation apparatuses are provided for simultaneously mounting or dismounting four twistlocks at the four corners of the container. This is advantageous for the optimization of the processing capacity of the loading or unloading terminal.
In a preferred embodiment the loading or unloading terminal is thus designed such that the portal is mobile. This is a convenient manner of adapting the processing position of the loading or unloading terminal to the prevailing conditions on the quayside.
It is desirable for the trolley to be provided near its corners with recesses for the accommodation of the twistlocks mounted at the corners of the container. This allows the container to be replaced on the trolley after the twistlocks have been mounted.
Another advantage is for each implementation apparatus to have in close proximity a supply tray for twistlocks. This ensures that there is a regulated stock of twistlocks, and the supply trays can serve as storage place.